How often should you back up your computer?
Short answer
Back up as often as the most work you can afford to lose: daily covers most people, and an hour of risk means automating it. Time Machine and File History already run on a schedule when a backup drive is attached, and a manual backup before any big change bounds the damage the change can do.
Back up as often as the most work you can afford to lose. If losing a day of files would hurt, back up daily. If an hour would hurt, automate it and let the computer handle the timing. Both Windows and macOS ship with tools that run on a schedule once you point them at a backup drive, so for most people the real question is not how often to back up but whether the tool is switched on and the drive is attached.[1]
Match the cadence to what you can afford to lose
Once a day covers most people's regular files. If you work actively all day, close the gap with continuous or automatic backups instead of a fixed time you have to remember. And take a backup by hand before any big change: an operating system update, a large migration to a new machine, new hardware. A fresh copy taken five minutes before the change bounds what the change itself can take with it.[1]
The built-in tools already run on a schedule
On a Mac, Time Machine backs up automatically to a USB drive or other external storage, covering apps, music, photos, email and documents. Its cadence is fixed: hourly backups for the past 24 hours, daily backups for the past month, and weekly backups for all previous months. The schedule only runs while the backup drive is attached; disconnect it and Time Machine picks the schedule back up when you reconnect.[1]
On Windows, File History does the same job. Once it is turned on, Microsoft says it continuously monitors your files and folders and makes regular backups to an external drive or a network location, without you saving copies by hand. It covers your libraries: the default ones such as Documents, Pictures, Videos and Music, with Desktop also included, plus any custom libraries you create. It keeps previous versions too, so an accidental delete or an unwanted change can be rolled back to an earlier copy. Microsoft describes those backups as regular and does not publish a default interval on the page, so confirm the cadence in your own settings rather than assume a number.[2]
Cloud sync is not the same as a backup
A sync folder keeps one copy in step across your devices, usually with a limited version history. That is availability, not backup: delete a file and the deletion syncs everywhere, and ransomware that encrypts your files encrypts the synced copy too. A sync service also leaves you without the offline copy that lets a backup set survive a bad day.[3]
Do not let a sync folder stand in for your second copy, and do not skip the test. CISA's ransomware guidance tells people to maintain offline, encrypted backups of data and to regularly test them, because a backup you have never restored from is a claim rather than a plan. Once a backup set exists, restore a few files from it on purpose and check they open.[3]
Put a structure under the schedule
Frequency answers when; structure answers where. The standard frame is 3-2-1: three copies of your data, on two different types of media, one copy offsite or offline. CISA's advice on offline, encrypted, regularly tested backups is the offline-and-tested leg of that structure. The built-in schedules above supply the copies; the structure is what keeps them from all sitting on the same shelf.[3]
Related reading
The 3-2-1 backup rule explained
How to store hard drives and SD cards
Sources
Facts on this page are cited to the publishers’ own documentation.
- [1] Apple — Back up your Mac with Time Machine (Apple Support). captured 2026-09-12.
- [2] Microsoft — Backup and restore with File History. captured 2026-09-12.
- [3] Cybersecurity and Infrastructure Security Agency (US) — Stop Ransomware | CISA. captured 2026-09-13.